Vion Pharmaceuticals Receives Response From FDA on Special Protocol Assessment for Onrigin(TM)

VION Pharmaceuticals Inc. announced today that it had received a response from the U.S. Food and Drug Administration (FDA) on a Special Protocol Assessment ("SPA") for its oncology therapeutic Onrigin(TM) (laromustine) Injection.

In January 2010, Vion filed a SPA with the FDA related to a randomized Phase II/III trial of Onrigin(TM) in combination with low-dose Ara-C (LDAC) in elderly patients with newly diagnosed acute myeloid leukemia (AML). In its response, the FDA requested that the Company conduct a separate Phase II trial of Onrigin(TM) and review the results of this trial with the FDA prior to conducting a Phase III trial.

The SPA process is intended to evaluate a Phase III protocol whose data will form the primary basis for an efficacy claim. The Phase II/III randomized trial for which the Company filed the SPA had been designed in response to the FDA's complete response letter to the Company's New Drug Application for Onrigin(TM) that required a randomized trial be conducted to support the approval of Onrigin(TM) for the treatment of AML.

On December 17, 2009, Vion filed a voluntary petition for relief under Chapter 11 of the United States Bankruptcy Code in the United States Bankruptcy Court in the District of Delaware (the "Court"). On February 11, 2010 Vion filed with the Court a Chapter 11 Plan of Liquidation ("Plan") and a related disclosure statement ("Disclosure Statement"). A hearing is scheduled to consider approval of the Disclosure Statement on March 1, 2010 and the Plan on April 6, 2010. Assuming that these hearings are held on or before the scheduled dates, and that the Plan is so confirmed at the scheduled hearing and goes effective by its terms, Vion anticipates that it will then no longer be a reporting company under the Securities Exchange Act of 1934, as amended.

Bankruptcy law does not permit solicitation of acceptances of the Plan until the Court approves the Disclosure Statement. Accordingly, this press release is not intended to be, nor should it be construed as a solicitation of a vote on the Plan. The Plan will become effective only if it receives the requisite stakeholder approval and is confirmed by the Court. There can be no assurance that the Court will approve the Disclosure Statement, that the stakeholders will approve the Plan, or that the Court will approve the Plan. Information in the Plan and the Disclosure Statement is subject to change whether as a result of an amendment to the Plan, actions of third parties or otherwise.